Power tools and methods

The present invention relates to a power tool (10， 20， 30， 40， 50)， the power tool-a support structure 21，-a pivot bearing 27 disposed on the support structure 21，-the pivot A shaft 8 supported on the support structure 21 via a bearing 27， a rotatable tool 1 coupled to the shaft 8， in particular a saw blade， a milling cutter or an abrasive wheel，-the tool 1 ) A strain gauge assembly 2 for detecting a mechanical variable 3 dependent on the force arising from-and the power tool 10， 20， 30， 40， 50 according to the detected mechanical parameter 3 And a control device 4 configured to identify events and / or states. The strain gauge assembly 2 is arranged in a fixed structure section 5 coupled to the pivot bearing 27 in a force transmission manner， but not in the pivot bearing 27. The invention relates to an electric tool (10， 20， 30， 40， 50) comprising: a support structure (21); a pivot bearing (27) mounted on the support structure (21); a shaft (8) mounted on the support structure (21) via the pivot bearing (27); a tool (1) which is rotatably coupled to the shaft (8)， in particular a saw blade， a milling cutter， or an abrasive wheel; a strain gauge assembly (2) for detecting a mechanical variable (3) which depends on a force originating from the tool (1); and a control device (4) which is designed to detect an occurrence and/or a state of the electric tool (10， 20， 30， 40， 50) according to the detected mechanical variable. The strain gauge assembly (2) is mounted on a stationary structure portion (5) coupled in a force-transmitting manner to the pivot bearing (27)， and is not mounted on the pivot bearing (27). The invention relates to an electric tool (10， 20， 30， 40， 50) comprising: a support structure (21); a pivot bearing (27) mounted on the support structure (21); a shaft (8) mounted on the support structure (21) via the pivot bearing (27); a tool (1) which is rotatably coupled to the shaft (8)， in particular a saw blade， a milling cutter， or an abrasive wheel; a strain gauge assembly (2) for detecting a mechanical variable (3) which depends on a force originating from the tool (1); and a control device (4) which is designed to detect an occurrence and/or a state of the electric tool (10， 20， 30， 40， 50) according to the detected mechanical variable. The strain gauge assembly (2) is mounted on a stationary structure portion (5) coupled in a force-transmitting manner to the pivot bearing (27)， and is not mounted on the pivot bearing (27).